Imported from ../bash-2.03.tar.gz.

examples/loadables/ln.c

@@ -0,0 +1,203 @@
+/* ln - make links */
+
+/* See Makefile for compilation details. */
+
+#include "config.h"
+
+#include "bashtypes.h"
+
+#if defined (HAVE_UNISTD_H)
+#  include <unistd.h>
+#endif
+
+#include "posixstat.h"
+
+#include <stdio.h>
+#include <errno.h>
+
+#include "builtins.h"
+#include "shell.h"
+#include "bashgetopt.h"
+
+#if !defined (errno)
+extern int errno;
+#endif
+
+#define LN_SYMLINK 0x01
+#define LN_UNLINK  0x02
+
+static Function *linkfn;
+static int dolink ();
+
+ln_builtin (list)
+     WORD_LIST *list;
+{
+  int rval, opt, flags;
+  WORD_LIST *l;
+  char *sdir;
+  struct stat sb;
+
+  flags = 0;
+  reset_internal_getopt ();
+  while ((opt = internal_getopt (list, "fs")) != -1)
+    {
+      switch (opt)
+	{
+	case 'f':
+	  flags |= LN_UNLINK;
+	  break;
+	case 's':
+	  flags |= LN_SYMLINK;
+	  break;
+	default:
+	  builtin_usage ();
+	  return (EX_USAGE);
+	}
+    }
+  list = loptend;
+
+  if (list == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+    
+  linkfn = (flags & LN_SYMLINK) ? symlink : link;  
+
+  if (list->next == 0)			/* ln target, equivalent to ln target . */
+    return (dolink (list->word->word, ".", flags));
+
+  if (list->next->next == 0)		/* ln target source */
+    return (dolink (list->word->word, list->next->word->word, flags));
+
+  /* ln target1 target2 ... directory */
+
+  /* find last argument: target directory, and make sure it's an existing
+     directory. */
+  for (l = list; l->next; l = l->next)  
+    ;
+  sdir = l->word->word;
+
+  if (stat(sdir, &sb) < 0)
+    {
+      builtin_error ("%s", sdir);
+      return (EXECUTION_FAILURE);
+    }
+
+  if (S_ISDIR (sb.st_mode) == 0)
+    {
+      builtin_usage ();
+      return (EX_USAGE);
+    }
+
+  for (rval = EXECUTION_SUCCESS; list != l; list = list->next)
+    rval += dolink (list->word->word, sdir, flags);
+  
+  return rval;
+}
+
+static char *
+mkdirpath (dir, file)
+     char *dir, *file;
+{
+  int dlen, flen;
+  char *ret;
+
+  dlen = strlen (dir);
+  flen = strlen (file);
+
+  ret = xmalloc (2 + dlen + flen);
+
+  strcpy (ret, dir);
+  if (ret[dlen - 1] != '/')
+    ret[dlen++] = '/';
+  strcpy (ret + dlen, file);
+  return ret;
+}
+
+#if defined (HAVE_LSTAT)
+#  define LSTAT lstat
+#else
+#  define LSTAT stat
+#endif
+
+static int
+dolink (src, dst, flags)
+     char *src, *dst;
+     int flags;
+{
+  struct stat ssb, dsb;
+  int exists;
+  char *dst_path, *p;
+
+  /* If we're not doing symlinks, the source must exist and not be a 
+     directory. */
+  if ((flags & LN_SYMLINK) == 0)
+    {
+      if (stat (src, &ssb) != 0)
+	{
+	  builtin_error ("%s: %s", src, strerror (errno));
+	  return (EXECUTION_FAILURE);
+	}
+      if (S_ISDIR (ssb.st_mode))
+	{
+	  errno = EISDIR;
+	  builtin_error ("%s: %s", src, strerror (errno));
+	  return (EXECUTION_FAILURE);
+	}
+    }
+
+  /* If the destination is a directory, create the final filename by appending
+     the basename of the source to the destination. */
+  dst_path = 0;
+  if ((stat (dst, &dsb) == 0) && S_ISDIR (dsb.st_mode))
+    {
+      if ((p = strrchr (src, '/')) == 0)
+	p = src;
+      else
+	p++;
+
+      dst_path = mkdirpath (dst, p);
+      dst = dst_path;
+    }
+
+  exists = LSTAT (dst, &dsb) == 0;
+
+  /* If -f was specified, and the destination exists, unlink it. */
+  if ((flags & LN_UNLINK) && exists && unlink (dst) != 0)
+    {
+      builtin_error ("%s: cannot unlink: %s", dst, strerror (errno));
+      FREE (dst_path);
+      return (EXECUTION_FAILURE);
+    }
+
+  /* Perform the link. */
+  if ((*linkfn) (src, dst) != 0)
+    {
+      builtin_error ("cannot link %s to %s: %s", dst, src, strerror (errno));
+      FREE (dst_path);
+      return (EXECUTION_FAILURE);
+    }
+
+  FREE (dst_path);
+  return (EXECUTION_SUCCESS);
+}
+
+char *ln_doc[] = {
+	"Create a new directory entry with the same modes as the original",
+	"file.  The -f option means to unlink any existing file, permitting",
+	"the link to occur.  The -s option means to create a symbolic link.",
+	"By default, ln makes hard links.",
+	(char *)NULL
+};
+
+/* The standard structure describing a builtin command.  bash keeps an array
+   of these structures. */
+struct builtin ln_struct = {
+	"ln",		/* builtin name */
+	ln_builtin,		/* function implementing the builtin */
+	BUILTIN_ENABLED,	/* initial flags for builtin */
+	ln_doc,		/* array of long documentation strings. */
+	"ln [-fs] file1 [file2] OR ln [-fs] file ... directory",	/* usage synopsis; becomes short_doc */
+	0			/* reserved for internal use */
+};